Hot Rod Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
229 Posts
Discussion Starter · #1 · (Edited)
Hey guys i've got a 1979 350 small block chevy and i'm in the market for some new heads and need some suggestions

the engine has the standard bore, stock pistons(dished), stock heads, mild cam which is just slightly more agressive than stock, double roller timing chain, performer eps intake, 600cfm edelbrock carb, block hugger headers, true dual exhaust with flowmaster mufflers(no cats)


looking to get a pair of heads that will raise my compression out of the smog era numbers and to have good throttle response and mid range torque and to have around 300 hp nothing too crazy

so with all that said any heads that would be a perfect match ? best combustion chamber size, intake runner size ? :confused:

edit just some extra info - engine is mated to 5 speed manual transmission and 3.73 rear gears
 

·
Registered
Joined
·
229 Posts
Discussion Starter · #3 ·
ap72 said:
195cc or smaller runners, 1.94" intake valve, 64cc chamber, preferably iron.
why iron ? seems like nowadays all the aftermarket brand heads come in aluminum and iron versions are rarer and not in stock as frequently as their aluminum counterparts
 

·
Registered
Joined
·
878 Posts
There is the erroneous perception that aluminum heads make "more" power. In fact, all things beng "equal" (flow, compressoin ratio, etc.) IRON heads make more power by NOT "soaking" as much heat out of the combustion process as aluminum, helping maintain the efficiency of the "burn". I often read "you can get away with more compressoin with aluminum without detonation". Somewhat true. "Get away with" is the error. You MUST run higher compression with aluminum to achieve the same power level. A prominent magazine did a test using Iron Eagles and Pro-1s, ported by the same man to the same specs. Chamber volume was equalized. The Iron Eagles made about 3-4% more across the range. After milling .030" off the Pro-1s to increase compression about 1/2 "point", they (aluminum) equalled the output of the iron.

From a machine shop's POV, aluminum is easy to "deal" with. That is, you get more for your "porting dollar" with aluminum. Aluminum is easier to repair in the case of a catestrophic failure. Aluminum is lighter (significantly). Add all this "up" and you can understand why aluminum is more popular. "Popular" and "better" aren't always synonimous...

FWIW

Jim
 

·
Banned
Joined
·
9,993 Posts
Mr. P-Body said:
There is the erroneous perception that aluminum heads make "more" power. In fact, all things beng "equal" (flow, compressoin ratio, etc.) IRON heads make more power by NOT "soaking" as much heat out of the combustion process as aluminum, helping maintain the efficiency of the "burn". I often read "you can get away with more compressoin with aluminum without detonation". Somewhat true. "Get away with" is the error. You MUST run higher compression with aluminum to achieve the same power level. A prominent magazine did a test using Iron Eagles and Pro-1s, ported by the same man to the same specs. Chamber volume was equalized. The Iron Eagles made about 3-4% more across the range. After milling .030" off the Pro-1s to increase compression about 1/2 "point", they (aluminum) equalled the output of the iron.

From a machine shop's POV, aluminum is easy to "deal" with. That is, you get more for your "porting dollar" with aluminum. Aluminum is easier to repair in the case of a catestrophic failure. Aluminum is lighter (significantly). Add all this "up" and you can understand why aluminum is more popular. "Popular" and "better" aren't always synonimous...

FWIW

Jim
That and with your dished pistons you'll be low on compression, going iron will slightly help that but its not a huge difference.
 

·
Not Considered a Senior Member
Joined
·
10,722 Posts
With the mild combo you got all you need is a set of Vortec heads and a Vortec intake. A set of RHS Vortec heads will fill the bill perfectly for your combo. You'll be amazed at how much power it'll pick up. Use the GM head gasket with .028 thickness couped with the 67cc chambers of the RHS heads will put your compression ratio right around the 9:1 mark which is ideal for your combo and it'll run fine on 87 octane pump gas.
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top